The invention is generally in the field of Raman spectroscopy (RAMAN) and more particularly to a sampling head for an apparatus and system designed for Raman spectroscopy measurements.
For various applications, methods are needed for determining the material constitution of a sample. One of the known methods is Raman spectroscopy (RAMAN), which involves shining a monochromatic light source, such as a laser, on a sample material and detecting the resulting scattered light. Most of the scattered light is the same frequency as the source. However, a very small amount of the scattered light (ca. 10-5% of the incident light intensity) is shifted in energy from the laser frequency due to interactions between the incident electromagnetic waves and the vibrational energy levels of the molecules in the sample. Plotting the intensity of this “shifted” light versus frequency results in a Raman spectrum of the sample.
The sample may in principle be solid, liquid or gaseous. In the case of a solid sample, the sample material or particle may of an irregular shape and/or difficult to hold while trying to focus the laser beam onto the sample's surface with a handheld or portable device. Efforts have been made to reduce the form factor of RAMAN devices into handheld devices, as evidenced by U.S. Pat. No. 7,505,128 to Zribi et al., and U.S. Pat. No. 8,699,020 to Zhou et al., however these devices still have not solved the problem of accurately identifying or evaluating samples of differing shapes and sizes. Therefore, there still exists a need for a handheld RAMAN device that addresses the aforementioned challenges.